In computer networks, message delivery and routing capabilities depend heavily on the concept of network addresses to identify the intended recipient(s) of a given message. One type of network address is a unicast address which identifies exactly one recipient as the destination of the message. For example, the following numerical representation under the Internet Protocol version 4 User Datagram Protocol (IPv4 UDP) identifies a unique address: 1.2.3.4:1234. Similarly, a commonly known domain-qualified electronic mail (e-mail) address may be: person@a.com.
The other type of network address is a multiple broadcast or multicast address which identifies a group of recipients who collectively form the destination(s) for the message(s). For example, a typical multicast address is a single address that targets multiple receivers: Numerical (e.g. IPv4 UDP) 232.1.2.3:1234 or domain-qualified (e.g. Mail) delivery-group@a.com.
Many addressing schemes exist today for multicast delivery, for example, the IPv4 UDP multicast scheme. However, current solutions today suffer from a variety of problems including scale limitations. For example, current multicast mechanisms typically cannot operate over extremely wide-area networks (e.g. the Internet). IPv4 UDP multicast, for example, is limited to the local subnet unless there is a global coordination of servers to perform the routing. Also, another drawback of the current implementation is the requirement for a centralized coordination. For example, existing multicast addressing schemes typically rely on a single centralized point of coordination to manage the set of nodes participating in a multicast delivery group. A federation of delivery groups, such as sending messages to sets of delivery groups managed by different nodes, is not supported.
Furthermore, existing practices may fail to ensure or guarantee address uniqueness. For example, current multicast addressing schemes that do not rely on a central coordination point are typically vulnerable to address collision, such as assigning the same address to two separate and non-equivalent nodes. There is also the issue of a finite upper bound on size of multicast address space. The existing IPv4 UDP multicast scheme uses an address space of 28 bits which limits the maximum number of simultaneous multicast groups to 228 groups. The upper bound on the number of nodes within a UDP multicast group is limited to the size of the subnet.